linux/sound/pci/emu10k1/voice.c
Oswald Buddenhagen a915d60426 ALSA: emu10k1: revamp playback voice allocator
Instead of separate voices, we now allocate non-interleaved channels,
which may in turn contain two interleaved voices each. The higher-level
code keeps only one pointer per channel. The channels are not allocated
in one block any more, as there is no reason to do that. As a
consequence of that, and because it is cleaner regardless, we now let
the allocator store these pointers at a specified location, rather than
returning only the first one and having the calling code deduce the
remaining ones.

Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230518140947.3725394-8-oswald.buddenhagen@gmx.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-05-20 10:16:20 +02:00

147 lines
3.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
* Creative Labs, Inc.
* Lee Revell <rlrevell@joe-job.com>
* Routines for control of EMU10K1 chips - voice manager
*
* Rewrote voice allocator for multichannel support - rlrevell 12/2004
*
* BUGS:
* --
*
* TODO:
* --
*/
#include <linux/time.h>
#include <linux/export.h>
#include <sound/core.h>
#include <sound/emu10k1.h>
/* Previously the voice allocator started at 0 every time. The new voice
* allocator uses a round robin scheme. The next free voice is tracked in
* the card record and each allocation begins where the last left off. The
* hardware requires stereo interleaved voices be aligned to an even/odd
* boundary.
* --rlrevell
*/
static int voice_alloc(struct snd_emu10k1 *emu, int type, int number,
struct snd_emu10k1_pcm *epcm, struct snd_emu10k1_voice **rvoice)
{
struct snd_emu10k1_voice *voice;
int i, j, k, skip;
for (i = emu->next_free_voice, j = 0; j < NUM_G; i = (i + skip) % NUM_G, j += skip) {
/*
dev_dbg(emu->card->dev, "i %d j %d next free %d!\n",
i, j, emu->next_free_voice);
*/
/* stereo voices must be even/odd */
if ((number > 1) && (i % 2)) {
skip = 1;
continue;
}
for (k = 0; k < number; k++) {
voice = &emu->voices[i + k];
if (voice->use) {
skip = k + 1;
goto next;
}
}
for (k = 0; k < number; k++) {
voice = &emu->voices[i + k];
voice->use = type;
voice->epcm = epcm;
/* dev_dbg(emu->card->dev, "allocated voice %d\n", i + k); */
}
voice->last = 1;
*rvoice = &emu->voices[i];
emu->next_free_voice = (i + number) % NUM_G;
return 0;
next: ;
}
return -ENOMEM; // -EBUSY would have been better
}
static void voice_free(struct snd_emu10k1 *emu,
struct snd_emu10k1_voice *pvoice)
{
if (pvoice->dirty)
snd_emu10k1_voice_init(emu, pvoice->number);
pvoice->interrupt = NULL;
pvoice->use = pvoice->dirty = pvoice->last = 0;
pvoice->epcm = NULL;
}
int snd_emu10k1_voice_alloc(struct snd_emu10k1 *emu, int type, int count, int channels,
struct snd_emu10k1_pcm *epcm, struct snd_emu10k1_voice **rvoice)
{
unsigned long flags;
int result;
if (snd_BUG_ON(!rvoice))
return -EINVAL;
if (snd_BUG_ON(!count))
return -EINVAL;
if (snd_BUG_ON(!channels))
return -EINVAL;
spin_lock_irqsave(&emu->voice_lock, flags);
for (int got = 0; got < channels; ) {
result = voice_alloc(emu, type, count, epcm, &rvoice[got]);
if (result == 0) {
got++;
/*
dev_dbg(emu->card->dev, "voice alloc - %i, %i of %i\n",
rvoice[got - 1]->number, got, want);
*/
continue;
}
if (type != EMU10K1_SYNTH && emu->get_synth_voice) {
/* free a voice from synth */
result = emu->get_synth_voice(emu);
if (result >= 0) {
voice_free(emu, &emu->voices[result]);
continue;
}
}
for (int i = 0; i < got; i++) {
for (int j = 0; j < count; j++)
voice_free(emu, rvoice[i] + j);
rvoice[i] = NULL;
}
break;
}
spin_unlock_irqrestore(&emu->voice_lock, flags);
return result;
}
EXPORT_SYMBOL(snd_emu10k1_voice_alloc);
int snd_emu10k1_voice_free(struct snd_emu10k1 *emu,
struct snd_emu10k1_voice *pvoice)
{
unsigned long flags;
int last;
if (snd_BUG_ON(!pvoice))
return -EINVAL;
spin_lock_irqsave(&emu->voice_lock, flags);
do {
last = pvoice->last;
voice_free(emu, pvoice++);
} while (!last);
spin_unlock_irqrestore(&emu->voice_lock, flags);
return 0;
}
EXPORT_SYMBOL(snd_emu10k1_voice_free);